Kahawai are voracious predators. Their diet consists primarily of:
- Smaller fish: Anchovies, sprats, pilchards, and other baitfish.
- Squid and octopus: Consumed when available.
- Crustaceans: Crabs, prawns, and others, especially during spawning season.
- Plankton: A primary food source for young kahawai.
Diet varies by size, age, location, and prey availability. Kahawai are opportunistic and have even been observed eating jellyfish.